Transient absorption spectroscopy of the iron(II) [Fe(phen)3]2+ complex: Study of the non-radiative relaxation of an isolated iron(II) complex

From Mononuclear to Dinuclear: Magnetic Properties of Transition Metal Complexes

“…These excitations are also optically allowed. TD-DFT/PBE0 predicts a slightly less intense absorption with respect to the MLCT states, contrasting experimental data, which clearly point at more intense LC excitations [17]. Finally, the metal-centered Fe-3d transitions appear around 420 and 570 nm but they are very weak due to the nearly octahedral coordination sphere of the Fe 2+ ion (forbidden d-d transition).…”

“…This is one of the reasons why more than twenty years after its discovery, LIESST e↵ect is still at the very center of the SCO research. The advances in short pulsed lasers enables researchers to extract information on the deactivation mechanism [15][16][17][18][19][20][21][22][23] and theoretical studies also contributed to the understanding of LIESST in octhedral Fe(II) complexes [60][61][62]. For Fe(III) complexes, the light irradiation induces ligand-tometal charge transfer transition (LMCT).…”

“…One important ingredient of LIESST that is possibly strongly dependent on the description of the environment is the vertical excitation spectrum of the initial LS state. Actually, the study of the transient absorption spectroscopy study of Tribollet et al on [Fe(phen) 3 ] 2+ (phen=1,10-phenanthroline) points to important solvent e↵ects on the excitation energies [17]. This was based on the mismatch of approximately 0.3 eV between the relative energies measured in experiment and those calculated for the related com-…”

“…Therefore, the synthesis of systems with bistability under standard conditions for which switching is fast and both states are su ciently long-lived (i.e., persistent) has become increasingly important over the last 50 years. In this area of research, the interconversion between two di↵erent spin states that can be triggered by light irradiation is especially important [15][16][17][18][19][20][21][22][23]. The bistability in molecular magnets involves the M S components of a given spin state and the population of the bistable states can be controlled by the application of an external magnetic field.…”

Impact of Spin State Transition on Vibrations of [Fe–(PM–BiA)2(NCS)2] and [Fe–(PM–PEA)2(NCS)2] Spin Crossover Compounds: Experimental and Theoretical Far IR and Raman Study

“…[21][22][23][24] Indeed it has been shown that an ultrashort laser pulse brings the complexes to an excited HS state, which, within less than 100 fs, relaxes through intersystem crossing to the LS state. [25] During this process, most of the electronic energy is damped through specific vibration modes. [23,24] Hence, in order to spot the vibration relaxation channels of photoexcited SCO complexes, it is important to identify these vibrations and their possible coupling with lattice vibration (i.e.…”